1. Field of the Invention
The present invention relates to a rotary camera for photographing an original image on a document sheet so that the photographed image is formed on a frame of microfilm roll. In operation of such a rotary camera, the microfilm is taken up at a rate which is reduced at a predetermined ratio to the moving speed of the document sheet that is conveyed by an appropriate conveying system.
2. Prior Art Statement
In the conventional rotary cameras of this type, the document sheet is conveyed through a passage which is formed by an assembly composed of a number of rollers and/or belts. However, the conventional system has inevitable problems that the sheets are not always inserted smoothly in-between the rollers or belts to cause jamming, breakdown, warping, crimping or skew of the sheet. These malfunctions often occur particularly when the thickness of the supplied document sheet is thin or the size thereof is relatively small. In addition, some kinds of sheet material are apt to be charged with static electricity and thus arise a problem that the smooth conveyance and discharge of the document sheet becomes more difficult.
The rollers or belts used in the conventional system are made of materials which are abraded during the long time use. As the progressive abrasion of rollers and/or belts, slippage of document sheets takes pace leading to undesired change in conveying speed. In such a case, the film conveying rate cannot be synchronized with the take-up speed of the film so that the quality of photographed image on the film is deteriorated.
Another disadvantage of the conventional system is that the roller and/or belt assembly is complicated so that the image-bearing light must be passed through an optical path of delicate and elaborate design in order that it is not interfered or obstructed by any one of the rollers or belts of the conveyor assembly. Particularly when the optical path is vicinal to the document feed port generally positioned at the front side or on the top face of the casing, there arises a problem that lights tend to enter from the document feed port. In order to prevent entrance of lights from outside of the casing, the casing should have a complicated shielding structure.
The conventional system has a further disadvantage that it is difficult to design a long light path without particular complication, leading to the result that the size of the total system becomes too large to ensure a long light path.
On the other hand, it is desirous that the document sheet is inserted into the system while observing the face on which the original image to be photographed is present.